The present invention relates to vacuum cleaners, and more particularly to wet/dry vacuum cleaners where liquid material in a tank of the vacuum cleaner is pumped out to waste.
Tank-type vacuum cleaners are capable of receiving dry materials such as debris or dirt and may also be used for suctioning liquids. When the tank is full, an upper vacuum assembly (which often includes a motor and an air impeller) is removed and the contents are dumped out. If the vacuum cleaner is used on liquid material, the tank, when at or near capacity, may be very heavy so that lifting the tank, to pour the contents into a sink or the like, is difficult. Even tilting the tank to pour the contents into a floor drain may be unwieldy when the liquid level in the tank is high.
One solution to the difficulties encountered in emptying liquid from vacuum tanks has been to provide an outlet at the bottom of the tank. Such a solution is satisfactory when the contents of the tank are emptied into a floor drain; however, if no floor or other low-placed drain is available the tank must be lifted to a sink or similar disposal site. In such cases the outlet at the bottom of the tank is of little value.
A second solution to emptying a vacuum tank of liquid is to provide a pump, usually with a motor located outside of or in the bottom of the tank. The pump removes liquid through a lower portion of the tank and expels it through a hose to waste. While such pumps are generally effective, they may be very costly. The pump requires not only a pump impeller and hoses but also its own electric motor, power cords, and switches. The expense of such items may be significant in the context of the overall cost of a vacuum cleaner, particularly those designed for residential use. Such pumps may also reduce the effective capacity of the vacuum tank or interfere with operation when the vacuum cleaner is used on dry materials. In addition, it may also be necessary to provide costly or complicated structures to prime the pump, if the pump is not located in the bottom of the tank.
Previous patents having a common assignee as the present application, such as U.S. Pat. No. 6,009,596, disclose a wet/dry vacuum cleaner having a self-priming pump for evacuating collected liquid. The devices disclosed and claimed therein provide significant improvements over the prior art. Certain aspects of the devices, however, have proven to be unnecessarily difficult or cumbersome. For example, the pump of the previous devices is provided in a split construction, in which an upper pump assembly is carried by an upper vacuum assembly and includes the pump impeller. A pump adapter assembly provides a lower portion of the pump, and is removably attached to the upper pump assembly. The pump adapter assembly defines a pump inlet and a pump outlet. To switch the vacuum cleaner from wet to dry pick-up, the upper vacuum assembly is removed from the tank and the pump adapter assembly is disconnected from the upper pump assembly. An outlet tube must also be disconnected from a discharge port before the pump adapter assembly may be completely removed from the tank.
In addition, the previous self-evacuating vacuum cleaners have employed priming apparatus which are overly difficult to actuate. In the ""596 patent, for example, a ball valve is disposed in the pump outlet pipe for controlling when the pump is primed. The ball valve includes a knob which may be used to move the ball valve to a closed position, a partially open position, and a fully open position, depending on the operating conditions and desired outcome. Furthermore, the knob may be left accidentally in one of the positions, thereby leading to unintended operation of the pump during subsequent use. As a result, the previous devices are overly complicated and difficult to use.
In accordance with one aspect of the present invention, a vacuum cleaner is provided comprising a tank having an inlet for receiving liquid material, the tank defining an interior. An air impeller housing has an opening in air flow communication with the tank interior. A driven air impeller is disposed inside the air impeller housing and defines an interior impeller space. The air impeller creates a low pressure area in the tank interior and a lower pressure area at the interior impeller space. A pump housing has an inlet in fluid communication with the tank interior and an outlet, and a powered pump impeller is disposed inside the pump housing. Outlet piping extends between the pump outlet and the tank exterior, and includes a flexible tube section. A pinch valve is positioned to engage the flexible tube section, the pinch valve moving between a first position allowing fluid flow through the tube section, and a second position, which prevents fluid flow through the tube section.
In accordance with another aspect of the present invention, a vacuum cleaner comprises a tank having an inlet for receiving liquid material, the tank defining an interior. An upper vacuum assembly is releasably attached to the tank, the upper vacuum assembly including a discharge outlet. An air impeller housing is carried by the upper vacuum assembly and has an opening in air flow communication with the tank interior. A driven air impeller is disposed inside the air impeller housing and defines an interior impeller space, the air impeller creating a low pressure area in the tank interior and a lower pressure area at the interior impeller space. A pump housing is carried by the upper vacuum assembly and has an inlet in fluid communication with the tank interior and an outlet. A powered pump impeller is disposed inside the pump housing. A pump outlet pipe extends from the pump outlet to the discharge outlet, the pump outlet pipe remaining in place between the pump outlet and the discharge outlet when the upper vacuum assembly is removed from the tank.
In accordance with an additional aspect of the present invention, a vacuum cleaner comprises a tank having an inlet for receiving liquid material, the tank defining an interior. An upper vacuum assembly is releasably attached to the tank, the upper vacuum assembly including a discharge outlet. A lid cage is carried by the upper vacuum assembly and has a periphery defining a filter receiving portion and a non-filter receiving portion. An air impeller housing is carried by the upper vacuum assembly and has an opening in air flow communication with the tank interior. A driven air impeller is disposed inside the air impeller housing and defines an interior impeller space, the air impeller creating a low pressure area in the tank interior and a lower pressure area at the interior impeller space. A pump housing is carried by the upper vacuum assembly and has an inlet in fluid communication with the tank interior and an outlet disposed inside the lid cage. A powered pump impeller is disposed inside the pump housing. A pump outlet pipe extends from the pump outlet to the discharge outlet, the pump outlet pipe passing through the non-filter receiving portion of the lid cage.
In accordance with a further aspect of the present invention, a vacuum cleaner comprises a tank having an inlet for receiving liquid material, the tank defining an interior. An air impeller housing has an inlet in air flow communication with the tank interior, and an air impeller is disposed inside the air impeller housing. A motor is provided for driving the air impeller, and a switch is operably coupled to the motor. A center tube is disposed inside the tank. A float is provided having a guide extension portion sized to slidably engage an exterior of the center tube, and a liquid engaging portion. The float is positioned inside the tank so that the guide extension portion is disposed about the center tube. A float rod extends from the float to the switch. In operation, the float slides upwardly along the center tube as the liquid collects in the tank thereby to actuate the switch via the float rod.
Other features and advantages are inherent in the vacuum cleaner claimed and disclosed or will become apparent to those skilled in the art from the following detailed description in conjunction with the accompanying drawings.